用STM32 CUBE工具生成代码 串口数据无输出。

int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* Enable I-Cache-------------------------------------------------------------*/
  SCB_EnableICache();

  /* Enable D-Cache-------------------------------------------------------------*/
  SCB_EnableDCache();

  /* MCU Configuration----------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* Configure the system clock */
  SystemClock_Config();

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART1_UART_Init();

  /* USER CODE BEGIN 2 */
        printf(" ");
        printf(" ------------------------------------------------- ");
        printf(" 你好 ");
//        HAL_UART_MspInit();
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */

}